The third Apollo flight announced on December 22, 1966, was the Apollo E mission - a test of the Apollo lunar module in high earth orbit. The Borman crew would be launched aboard a Saturn V, and put into a very high earth orbit. In mid-1968 Collins had to leave the crew due to a medical problem, and was replaced by Lovell. By late 1968, Apollo 7 had flown the Apollo C mission, but delays with the lunar module meant that neither the D or E profile missions could be flown. In order to beat the Russians around the moon, it was decided that the E mission would be cancelled and instead Borman's crew would fly an Apollo CSM into lunar orbit. This became Apollo 8.